East Kunlun Dulan cocoa sand - Section can be special mafic - ultramafic rocks of the geological features, age and tectonic significance of the formation of

Title: East Kunlun Dulan cocoa sand - Section can be special mafic - ultramafic rocks of the geological features, age and tectonic significance of the formation ofAuthors: Feng YunDegree-granting units: Chang'an UniversityKeywords: mafic - ultramafic rocks;; LA-ICP-MS zircon U-Pb age;; SSZ-type ophiolite;; back-arc spreading small ocean basin;; early Paleozoic;; Dulan cocoa sand;; East Kunlun orogenic beltSummary:

East Kunlun orogenic belt is a complex continent, including a number of important tectonic suture zone. Author in the East Kunlun area west of the eastern section of water springs are blue cocoa sand - Section can be special areas of the west side of the Dawa Te 1:50000 regional geological investigation, we found a set of predecessors have not reported mafic - ultramafic rock belt, ophiolite Qingshuiquan suspected part. The study of the combination of sets rock the Neodymium Magnets East Kunlun area will help to solve a lot of controversy of the early Paleozoic tectonic framework issues, and further explore the eastern section of the East Kunlun Mountains area in the early Paleozoic tectonic evolution history.

In this paper the theory of plate tectonics and continental dynamics to explore the guiding ideology for academic research, by field geological mapping and rock samples for detailed indoor testing and analysis, and the set of combinations of wild rock geology, petrology, geochemistry and isotopic dating systems in such areas as research, mainly to obtain the following understanding:

1, East Kunlun Dulan cocoa sand - Section can identify a set of special regional mafic - ultramafic rocks, rocks are mainly serpentinized peridotite, lherzolite, pyroxenite and gabbro, alteration of basalt.

2, the combination of mafic rocks are oceanic island arc tholeiite and calc-alkaline basalt transition type, the more enriched Rb, Ba and other large ion lithophile elements, light and heavy REE fractionation is more obvious, and T-MORB-type transition characteristics of mid-ocean ridge basalts are similar; and ultramafic rocks are alkali for the poor performance of high-magnesium iron, enriched Rb, Ba, Nb, Ta and Cr and other elements, light and heavy REE fractionation obvious that the continental crust by mixing stained more strongly, and from a more enriched mantle source oceanic lithosphere.

3, the sets of rocks are believed to be a typical Yanyan dismembered ophiolite block, most likely formed in a back-arc basin or a small ocean basin ridge expansion environment, according to the ophiolite SSZ-type or category should belong to the East Mediterranean type.

4, the isotopic age of gabbro test limit its LA-ICP-MS zircon U-Pb age of (509.4 ± 6.8) Ma (MSWD = 1.4), indicating the formation of the Early Paleozoic in the Cambrian;

5, mafic - ultramafic rocks with a combination of rock and spring water has the same ophiolite formation age and similar geochemical characteristics, therefore, should be under the water to be dismembered ophiolite spring as part of that spring water http://www.everbeenmagnet.com/en/products/110-sintered-neodymium-magnets ophiolite space west direction along the Nan Xixi Spread.

6, East Kunlun Qingshuiquan - Cocoa sand in the region in the Early Paleozoic Cambrian there is an expansion of the small ocean basin, most likely after the Rodinia supercontinent cracked by the former East Kunlun eastern edge of the Tethys expansion.Degree Year: 2010